Apparatus for manufacturing hollow resin products

ABSTRACT

An apparatus for manufacturing hollow resin products. The apparatus includes an extruder for extruding a tubular resin material and cutting the material into a parison with a specified length; a blow molding machine having an upper mold and a lower mold which form a cavity of a specified shape inside; and a parison delivering machine for receiving the parison from the extruder and feeding the parison into the cavity of the lower mold. The parison delivering machine includes a conveyer which has parison feeder for feeding a parison longitudinally from an inlet to an outlet, a driver for driving the feeder, and at least four shafts which serve as pivots of three-dimensional movement of the conveyor.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus and a method formanufacturing hollow resin products, such as hoses and pipes, by blowmolding.

2. Description of Related Art

Hoses to be provided in the engine room of an automobile, such as adefroster hose, an air hose, a radiator hose, etc. are curvedtwo-dimensionally or three-dimensionally as shown in FIG. 4 tofacilitate the fitting therein. Such a complicatedly curved resinarticle is conventionally produced by blow molding which has steps of:making a parison by cutting a resin material extruded from a die head ofan extruder; feeding the parison into a cavity of a mold; and injectingcompressed air into the parison. The most difficult step in the blowmolding is the step of feeding the parison into the cavity of the mold(ordinarily a lower mold). With respect to this step, Japanese Laid OpenPublication No. 53-56262 suggested moving the mold, and Japanese LaidOpen Publication No. 55-21239 suggested moving the die head of theextruder. However, the necessity of moving the mold or the die headcauses the apparatus to become large.

Further, Japanese Patent Publication No. 4-4931 disclosed a method usinga conveyer provided between an extruder and a mold. The method has stepsof: placing a parison extruded from the extruder on the conveyer; andmoving the conveyer two-dimensionally or three-dimensionally so as tofeed the parison into the cavity correctly. The conveyer is movedhorizontally (in the X direction and in the Y direction) and ifnecessary vertically (in the Z direction). However, in this method, themoving speed of the conveyer is slow, and accordingly it takes a longtime to deliver the parison to the mold. Moreover, while the parison isbeing fed into the cavity, the parison may be twisted by curved portionsof the cavity (portions 42b and 42c of the cavity 42 shown in FIG. 3which corresponds to the curved portions 2 and 3 of the hose 1 shown inFIG. 4).

In the blow molding, the temperature of the parison is important. Theportions of the parison which are in contact with the conveyer and themold are cooled more easily than the other portions, and at the time ofinjection of compressed air, the portions at a lower temperature do notexpand so much as the other portions. Consequently, the wall thicknessthere becomes larger, and the molded product has a varied wallthickness.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an apparatus formanufacturing hollow resin products which feeds a parison into a cavityof a mold speedily and smoothly without twisting the parison at curvedportions.

Another object of the present invention is to provide an apparatus formanufacturing hollow resin products which has a good productivity.

A further object of the present invention is to provide a conveyer whichreceives a parison from an extruder smoothly and feeds the parison intoa cavity of a lower mold smoothly.

Another object of the present invention is to provide a conveyer fordelivering a parison from an extruder to a lower mold, the conveyerhaving a prevention against variation of the wall thickness of aproduct.

Another object of the present invention is to provide a method ofmanufacturing hollow resin products which can prevent variation of thewall thickness of a product.

In order to attain the objects above, a manufacturing apparatusaccording to the present invention comprises an extruder for extruding atubular resin material and cutting the material into a parison with aspecified length; a blow molding machine which has a cavity between anupper mold and a lower mold; and a parison delivering machine forreceiving a parison from the extruder and feeding the parison into thecavity of the blow molding machine. The parison delivering machine has:a conveyer which has parison feeding means for feeding the parisonlongitudinally from an inlet to an outlet; and at least four shaftswhich serve as pivots of three-dimensional movement of the conveyer.

In the apparatus of the present invention, the parison extruded from theextruder is placed on the parison feeding means (for example, acaterpillar, a belt or a group of rollers) of the conveyer through theinlet, and with a drive of the feeding means, the parison is fed to theoutlet and then into the cavity of the molding machine. The conveyerrotates and swings by using the four shafts as pivots, and the outlet ofthe conveyer can move along the cavity even if the cavity isthree-dimensionally curved. Thus, because of the three-dimensionalmovement of the conveyer, the parison can be fed into the cavityspeedily with no twists.

The four shafts mean a shaft for a movement of the conveyer in parallelto the floor, a shaft for a forward/backward movement of the conveyer ashaft for an upward/downward movement of the conveyer, and a shaft for ahorizontal rotation of the conveyer on its central portion in thelongitudinal dimension.

In the manufacturing apparatus, it is preferred that three blow moldingmachines are provided to work with one extruder and one parisondelivering machine. While a parison delivered to a first blow moldingmachine is being subjected to blow molding and cooling, the parisondelivering machine delivers a parison to a second molding machine andthen delivers a parison to a third molding machine. By operating thethree blow molding machines continuously in this way, the manufacturingapparatus can manufacture hollow resin products efficiently.

A conveyer according to the present invention has parison feeding meanscomprising a plurality of segments connected endlessly, the segmentsbeing substantially semicircular so as to agree with the shape of aparison; and driving means for driving the parison feeding means. Thesemicircular segments form a semicylindrical feeding means, and becauseof the semicylindrical shape, the feeding means can feed a parison,which is hot and soft, smoothly without distorting the parison.

By providing heating means for heating the segments, the parison isprevented from cooling down. Further, if the feeding means and theheating means are enclosed with a heat insulator, it will stabilize theinternal temperature of the conveyer and secure the operator from theheat. If guide rollers are provided at the inlet and the outlet of theconveyer, the parison feeding will be smoother.

In a manufacturing method according to the present invention, a parisonis fed from a conveyer into a lower mold of a blow molding machine suchthat a side of the parison which has been in contact with the conveyeris put into contact with the lower mold, and the conveyer is at a highertemperature than the parison. If the temperature of the conveyer islower than that of the parison, the side of the parison in contact withthe conveyer will be cooled, and the side will be further cooled bycontact with the lower mold. Then, when the parison is blow-molded, thecooled portion will have a thicker wall. In the method of the presentinvention, however, since the temperature of the conveyer is higher thanthat of the parison, the side of the parison in contact with theconveyer is heated, and when the side comes into contact with the lowermold, the side becomes the same temperature as the other side. Then, theparison can be blow-molded into a product with an even wall thickness.Also, it occasionally happens that the parison gets an impression of theconveyer on the side in contact with the conveyer, but the heating ofthe side helps erase the impression.

In another manufacturing method according to the present invention, aparison is fed from a conveyer into a lower mold of a blow moldingmachine such that a side of the parison which has been out of contactwith the conveyer is put into contact with the lower mold. As mentioned,it occasionally happens that the parison gets an impression of theconveyer on the side in contact with the conveyer. Then, if the sidewith the impression is put into contact with the lower mold, the sidewill be cooled, and the impression will be fixed thereon. In thismethod, however, the side which has been out of contact with theconveyer is put into contact with the lower mold, and it never happensthat the side with the impression is cooled by contact with the lowermold. Then, when the parison is blow-molded, the side with theimpression is pushed against the upper mold, and the impressiondisappears. In this method, further, if the conveyer is at a lowertemperature than the parison, when the parison is fed into the lowermold from the conveyer, the side which was in contact with the conveyerand the side which was out of contact with the conveyer will be the sametemperature, resulting in an even wall thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will beapparent from the following description with reference to theaccompanying drawings, in which:

FIG. 1 is a plan view of a manufacturing system according to the presentinvention, showing the arrangement of components;

FIG. 2 is a front view of a robot which is a component of themanufacturing system of FIG. 1;

FIG. 3 is a perspective view of a mold for blow molding;

FIG. 4 is a hose molded by the mold of FIG. 3;

FIG. 5 is a perspective view of a caterpillar segment which is acomponent of parison feeding means;

FIG. 6 is a front view of a conveyer according to the present invention,showing the right half thereof;

FIG. 7 is a front view of the conveyer, showing the left half thereof;

FIG. 8 is a sectional view of the conveyer, taken along the lineVIII--VIII in FIG. 6;

FIG. 9 is a sectional view of the conveyer, taken along the line IX--IXin FIG. 6;

FIG. 10 is a sectional view of the conveyer, taken along the line X--Xin FIG. 7;

FIG. 11 is a front view of the robot of FIG. 2 which is provided withthe conveyer of FIGS. 6 through 10;

FIG. 12 is an illustration of a first way of putting a parison into acavity;

FIG. 13 is an illustration of a second way of putting a parison into acavity; and

FIG. 14 is a time chart showing one cycle of operation of themanufacturing system of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention are hereinafterdescribed with reference to the accompanying drawings.

FIG. 1 is a plan view of a whole apparatus for manufacturing hollowresin products. A parison deliver robot 10 is disposed in the center,and an extruder 30 and three blow molding machines 40 are disposed inthe periphery. The extruder 30 is of a conventional type which extrudesa tubular resin material downward from a die head 31 and cuts the resinmaterial into a parison with a specified length. Around the extruder 30,a robot control board 35, a centralized control board 36, and closingcontrol boards 37 are disposed.

As shown in FIG. 3, each of the blow molding machines 40 has a lowermold 41 and an upper mold 45, and is open and closed by moving up anddown the upper mold 45. The lower mold 41 is slidable in a directionindicated by the arrow A and in the opposite direction. The lower mold41 is moved in the direction indicated by the arrow A to be set in aparison receiving position. FIG. 1 shows a state wherein the lower molds41 of the blow molding machines 40 are set in the respective parisonreceiving positions. The molds 41 and 45 have a cavity 42 which isidentical with the product, a hose 1 (see FIG. 4), although the portionin the upper mold 45 is not seen in FIG. 3. Further, the lower mold 41has a nozzle hole 43 which extends from an edge to the cavity 42.

Additionally, a blow air unit 100 is provided to inject compressed airto parisons placed in the molds 41 and 45 of the blow molding machines40.

Next, referring to FIG. 2, the robot 10 is described.

The robot 10 is to receive parisons extruded from the die head 31 of theextruder 30 on a conveyer 25 and to deliver the parisons to the cavities42 of the lower molds 41 set in the parison receiving positions one byone. A base column 11 is fixed on a floor G, and a first support column13 is fitted to the base column 11 via a shaft 12 to be pivotable on theshaft 12 in a direction indicated by the arrow a. A second supportcolumn 15 is provided over the first support column 13 and is connectedthereto by a shaft 14. The second support column 15 is pivotable on theshaft 14 in a direction indicated by the arrow b. A beam 17 is providedover the second support column 15 and is connected thereto by a shaft16. The beam 17 is pivotable on the shaft 16 in a direction indicated bythe arrow c. The rear side of the beam 17 is supported by the firstsupport column 13 via links 18a and 18b. On the front side of the beam17, a first arm 19 is provided to be rotatable in a direction indicatedby the arrow d. A second arm 21 is fitted to the first arm 19 at thefront end via a shaft 20 to be pivotable on the shaft 20 in a directionindicated by the arrow e. Further, a holder 22 is fitted to the arm 21to be rotatable in a direction indicated by the arrow f.

The conveyer 25 is held by the holder 22 in the central portion in thelongitudinal dimension. The conveyer 25 has a hollow 26 extending in thelongitudinal direction. One end of the hollow 26 serves as a parisoninlet 26b, and the other end thereof serves as a parison outlet 26b. Ona wall of the hollow 26, a number of rollers 27 are provided to berotatable counterclockwise in FIG. 2.

The robot 10 has driving means to rotate the first support column 13,the second support column 15, the beam 17, the first arm 19, the secondarm 21 and the holder 22 in the directions a, b, c, d, e and frespectively, and further has driving means to rotate the rollers 27,although the driving means are not illustrated.

The shaft 12 extends vertically to the floor G, and by the pivoting ofthe first support column 13 on the shaft 12, the conveyer 25 moves inparallel to the floor G. Thereby, the conveyer 25 can move between aposition under the die head 31 of the extruder 30 and positions abovethe lower molds 41 which are set in the parison receiving positions.

The second support column 15 pivots on the shaft 14 in the directionindicated by the arrow b, and thereby, the conveyer 25 can move backwardand forward as indicated by the arrow B. The beam 17 pivots on the shaft16 in the direction indicated by the arrow c, and thereby, the conveyer25 can move up and down. The first arm 19 rotates on its axis 19a in thedirection indicated by the arrow d, and thereby, the conveyer 25 swingsright and left (in a direction perpendicular to the direction indicatedby the arrow B), that is, rolls. The second arm 21 pivots on the shaft20 in the direction indicated by the arrow e, and thereby, the conveyer25 swings backward and forward, that is, pitches. The holder 22 rotateson its axis 22a in the direction indicated by the arrow f, and thereby,the conveyer 25 rotates.

Now, a process of delivering a parison to the lower mold 41 of one ofthe blow molding machines 40 is described.

First, the conveyer 25 is rotated such that the inlet 26a will comeright under the die head 31 of the extruder 30. A parison is extrudeddownward from the die head 31 and is guided onto the rollers 27 throughthe inlet 26a. The rollers 27 are rotated to feed the parison to theoutlet 26b. The circumferential speed of the rollers 27 is equal to theparison extruding speed.

Next, the conveyer 25 is moved to a position above the lower mold 41which is drawn from the blow molding machine 40. Further, the conveyer25 is rotated and/or moved backward and forward and/or up and down suchthat the outlet 26b will come right above an end 42a of the cavity 42.Then, the rollers 27 are driven to feed the parison out through theoutlet 26b, and simultaneously the conveyer 25 is rotated and/or movedbackward and forward and/or up and down such that the outlet 26b canmove along the cavity 42. Thus, the parison is put in the cavity 42. Thefeed of the parison and the movement of the outlet 26b along the cavity42 are at the same speed.

After feeding the parison into the cavity 42, the conveyer 25 isreturned under the die head 31. Meanwhile, the lower mold 41 is returnedinside the blow molding machine 40, and the lower mold 41 and the uppermold 45 are closed. The molds 41 and 45 are kept at a specifiedtemperature. Then, a nozzle (not illustrated) is inserted through thenozzle hole 43, and compressed air is injected into the parison. Thus,blow molding is carried out.

As described above, in this embodiment, since the movement of theconveyer 25 is controlled by columns and arms pivotable on six shafts,the conveyer 25 can move along the three-dimensionally curved cavity 42smoothly and speedily, which results in shortening of the time of theparison feeding process. The rotation of the holder 22 in the directionindicated by the arrow f and the rotation of the first arm 19 in thedirection indicated by the arrow d are especially effective. Because ofthese rotations, the conveyer 25 can swing and rotate to feed theparison into the cavity 42 with three-dimensional curves 42b and 42c,without twisting the parison.

In the robot 10, the structure of combination of the shafts and thedriving means may be of any type. Although six shafts are used in theembodiment, what are indispensable are only four shafts, namely, thefirst shaft 12, the second shaft 14, the third shaft 16 and the sixthshaft 22a.

In the embodiment, rollers 27 are provided inside the conveyer 25 asparison feeding means, but it is possible to use a belt instead of therollers 27. It is preferred for stable feeding of the parison that therollers or the belt is semicircular and concave in the central portionto agree with the shape of the parison.

Further, the parison feeding means may be a caterpillar. In this case, aplurality of segments 28, one of which is illustrated in FIG. 5, aredisposed with no intervals around an endless chain, and the parison isreceived on semicircular surfaces 28a of the segments 28.

Next, referring to FIGS. 6 through 10, another conveyer 50 which can beused instead of the conveyer 25 is described.

The conveyer 50 has caterpillar type parison feeding means. A housing 51of the conveyer 50 has a parison inlet 52 at an end and a parison outlet53 at the other end and is held by the holder 22 of the robot 10 in thecentral portion. The housing 51 has a rectangular section as seen inFIGS. 8 through 10 and has a two-layer heat insulator 54. FIG. 11 showsa state wherein the conveyer 50 is fitted to the robot 10. The robot 10of FIG. 11 has the same structure as that of FIG. 2, and the portionsare provided with the same reference symbols as in FIG. 2.

In the housing 51, a chain 63 is laid between sprockets 61 and 62 whichare disposed at the front portion and the rear portion respectively. Aplurality of segments 65 are disposed around the chain 63, and bases 65aof the segments 65 are fixed on the chain 63. Each of the segments 65has a similar shape to the segment 28 illustrated in FIG. 5. The base65a has an arc inner surface, and side walls are extended upward fromthe arc inner surface, slanting outwardly at an angle of approximately45 degrees and ending in upright. The segments 65 fitted to the chain 63have no intervals thereamong, and they form a substantiallysemicylindrical feed path in a linear portion of the chain 63. A motor66 (see FIG. 9) is provided in the holder 22 of the robot 10. The chain63 is driven by the motor 66 via the sprocket 67, a coupling 68 and ashaft 69, and rotates counterclockwise in FIG. 7. The rotating speed ispreferably changeable to correspond to the parison extruding speed ofthe extruder 30 and the parison feeding speed.

At the inlet 52 of the housing 51, as shown in FIG. 8, guide rollers 70,each of which thins in the central portion, are provided. These guiderollers 70 are to guide a parison extruded from the die head 31 of theextruder 30 to the segments 65. The guide rollers 70 are driven by themotor 66 via the sprocket 67, a chain and idle gears 73.

At the outlet 53 of the housing 51, as shown in FIG. 10, guide rollers75, each of which thins in the central portion, are provided. Theseguide rollers 75 are to guide a parison fed by the segments 65 to alower mold 41. The guide rollers 75 are driven by the motor 66 via thesprocket 62, a chain and idle gears 76.

Further, heaters 80 are provided inside the housing 51. Four heaters arearound the inlet 52, four heaters are in the central portion, and fourheaters are around the outlet 53. These heaters 80 heat up the segments65 to prevent a parison fed thereby from cooling down or to positivelyheat up the parison. The heaters 80 are controllable individually. Theconveyer 50 is open at the inlet 52 and at the outlet 53, and thesegments 65 around the inlet 52 and the outlet 53 easily cool down.Therefore, the heaters 80 therearound are set to a higher temperature.The conveyer 50, like the conveyer 25, is suspended by the robot 10 anddelivers parisons to the lower molds 41 in a slanting posture with theoutlet 53 lower. In this state, the portion around the outlet 53 coolsdown the most quickly because heat diffuses upward. Therefore, it ispreferred that the heaters 80 around the outlet 53 are set to arelatively high temperature.

The temperature setting of the heaters 80 is closely related to the wayof putting a parison into a lower mold 41.

A first way is, as shown in FIG. 12, to put the side P₁ of a parison Pwhich has been in contact with the segments 65 into contact with thecavity 42 of a lower mold 41. In this ease, the conveyer 50 moves in adirection indicated by the arrow Y. The parison P is cooled andsimultaneously hardened a little by contact with the cavity 42. At thenext step of injecting compressed air into the parison P, the cooledportion of the parison P does not expand so much as the other portions,resulting in a varied wall thickness. In this first way, the heaters 80are set to a temperature to keep the segments 65 at a higher temperaturethan that of the parison P. Thereby, the segment contact side P₁ of theparison P keeps at a relatively high temperature, and even when the sideP₁ is cooled by contact with the cavity 42, the side P₁ can maintainsubstantially the same temperature as the other side P₂ which has beenout of contact with the segments 65, resulting in an even wallthickness. It occasionally happens that the parison P gets an impressionof the segments 65 on the segment contact side P₁. However, if the sideP₁ is heated sufficiently by the heaters 80, the impression willdisappear when the parison P is pushed against the cavity 42 byinjection of compressed air.

A second way is, as shown in FIG. 13, to put the side P₂ of a parison Pwhich has been out of contact with the segments 65 into contact with thecavity 42 of a lower mold 41. In this case, the conveyer 50 moves in adirection indicated by the arrow Y'. As mentioned, the parison P mayhave an impression of the segments 65 on the side P₁ which has been incontact with the segments 65. In this second way, the non-contact sideP₂, not the contact side P₁, is put into contact with the cavity 42, andthe contact side P₁ is not so cooled that the impression will be fixedthereon. In the second way, since the non-contact side P₂ is cooled bycontact with the cavity 42, the heaters 80 are set to a temperature tokeep the segments 65 at a lower temperature than that of the parison P.Thereby, when the parison P is put into the cavity 42, the contact sideP₁ and the non-contact side P₂ are the same temperature, resulting in aneven wall thickness.

The temperature setting of the heaters 80 depending on the way ofputting a parison into a cavity is applicable to a belt type conveyerand a roller type conveyer as well as the caterpillar type conveyer 50.Further, the controllers of these conveyers do not have to be robotslike the six-shaft robot 10, and the conveyers may be controlled in anysimpler structure.

Next, referring to FIG. 14, action timing of a manufacturing systemwhich comprises the extruder 30, the robot 10, the conveyer 25 or 50,and the three blow molding machines 40 is described. The blow moldingmachine disposed in the left upper side in FIG. 1 is referred to asfirst blow molding machine, the one disposed in the left lower side inFIG. 1 is referred to as second blow molding machine, and the onedisposed in the right lower side in FIG. 1 is referred to as third blowmolding machine.

A period from S to S' is one cycle, and the cycle is repeated.

The extruder 30 carries out measuring of the material during a time Aand extrusion of a parison during a time B. The robot 10 moves theconveyer 25 or 50 to a parison receiving position (under the die head31) or to a parison feeding position (above a lower mold 41) during atime C. Each of the blow molding machines 40 moves the lower mold 41 tothe parison receiving position during a time E₁ and to the closingposition during a time E₂. The mold opening and the mold closing arecarried out during a time F₁ and during a time F₂ respectively. Further,compressed air is injected into a parison during a time G, and theparison is cooled down during a time H while keeping a specifiedinternal pressure.

In this procedure, a single robot 10 and three blow molding machines 40can be used efficiently, and the productivity is greatly improved.

The arrangement of the three blow molding machines 40 is not limited tothe one shown in FIG. 1. The blow molding machines 40 can be arrangedradially with the robot 10 in the center such that the lower molds 41are drawn to the respective parison receiving positions inwardly in theradial direction.

Although the present invention has been described in connection with thepreferred embodiments, it is to be noted that various changes andmodifications are possible to those who are skilled in the art. Suchchanges and modifications are to be understood as being within the scopeof the present invention.

What is claimed is:
 1. An apparatus for manufacturing hollow resinproducts, the apparatus comprising:an extruder for extruding a tubularresin material and cutting the material into a parison with a specifiedlength; a blow molding machine having an upper mold and a lower moldwhich form a cavity of a specified shape inside; and a parisondelivering machine for receiving the parison from the extruder andfeeding the parison into the cavity of the lower mold, the parisondelivering machine comprising a conveyer which has a parison feeder forfeeding a parison longitudinally from an inlet to an outlet, driver fordriving the feeder and at least four shafts which serve as pivots ofthree-dimensional movement of the conveyor wherein the parisondelivering machine comprises six shafts, in which:a first shaft ispositioned vertically to a floor and serves as a pivot of a movement ofthe conveyer in parallel to the floor; a second shaft is positioned onthe first shaft and serves as a pivot of a forward/backward movement ofthe conveyer; a third shaft is positioned on the second shaft and servesas a pivot of an upward/downward movement of the conveyer; a fourthshaft is positioned on the third shaft and serves as a pivot of a swingof the conveyer in a plane perpendicular to a parison feeding direction;a fifth shaft is positioned on the fourth shaft and serves as a pivot ofa swing of the conveyer in a plane including the parison feedingdirection; and a sixth shaft is positioned on the fifth shaft and servesas a pivot of a rotation in substantially a horizontal plane on acentral portion of the conveyer in the longitudinal dimension.
 2. Anapparatus for manufacturing hollow resin products as claimed in claim 1,wherein three blow molding machines are provided to work with oneextruder and one parison delivering machine.
 3. An apparatus formanufacturing hollow resin products as claimed in claim 2, wherein:eachof the blow molding machines has a lower mold which is movable between aclosing position and a parison receiving position and an upper moldwhich is set in the closing position; and the parison receiving positionof each lower mold is under a moving range of the conveyer.
 4. Anapparatus for manufacturing hollow resin products as claimed in claim 1,wherein:the parison feeder of the conveyer of the parison deliveringmachine comprises a plurality of segments connected endlessly, thesegments being substantially semi-circular so as to agree with the shapeof the parison.
 5. An apparatus for manufacturing hollow resin productsas claimed in claim 4, wherein:the conveyer is at a higher temperaturethan the parison; and when the parison is fed from the conveyer into thelower mold, a side of the parison which has been in contact with theconveyer is put into contact with the lower mold.
 6. An apparatus formanufacturing hollow resin products as claimed in claim 4, wherein theconveyer comprises a heater for heating the segments.
 7. An apparatusfor manufacturing hollow resin products as claimed in claim 6, whereinthe heater has a plurality of heaters of which set temperatures areindividually adjustable.
 8. An apparatus for manufacturing hollow resinproducts as in claim 4, wherein when the parison is fed from theconveyor into the lower mold, a side of the parison which has been outof contact with the conveyor is put into contact with the mold.
 9. Anapparatus for manufacturing hollow resin products as in claim 8, whereinthe conveyor is at a lower temperature than the parison.